<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app">
        <ul>
            <li v-for="(item, index) in arr" :key="index">
                <span>{{ item }}</span>
                <button @click="del(index)">删除</button>
            </li>
        </ul>
        <button @click="add">生成</button>
    </div>
    <script src="./lib/vue.js"></script>
    <script>
        new Vue({
            el: '#app',
            data: {
                arr: [1, 2, 3]
            },
            methods: {
                add() {
                    this.arr.push(Math.floor(Math.random() * (20 - 0) + 0 ))
                },
                del(index) {
                    this.arr.splice(index, 1)
                }
            }
        })
    </script>
</body>
</html>